Alignment mechanism



P 1957 G. CAMERINI ALIGNMENT MECHANISM Filed March 4, 1965 United StatesPatent Office 3,342,480 Patented Sept. 19, 1967 3,342,480 ALIGNMENTMECHANISM Giorgio Camerini, deceased, late of Milan, Italy, by Laura VedCamerini Nasso, Milan, Anna Maria Vigevaui Camerini, Milan, Luisella VedBosio Camerini,'Milan, Franco Carnerini, Milan, and Gianni Camerini,Milan, and Margherita Camerini, in Violin, Rome, Italy, heirs, assignorsto Natro Cellulosa S.p.A., Industria Imballaggi Carta, Milan, Italy, acorporation of Italy Filed Mar. 4, 1965, Ser. No. 440,061 Claimspriority, application Italy, Mar. 6, 1964, 5,079/64 9 Claims. (Cl.271-58) This is a continuation-impart of copending applications, Ser.No. 368,162, filed May 18, 1964, and Ser. No. 370,- 451, filed May 27,1964, now abandoned.

This invention relates to improvements in apparatus for forming bagclosures, and is especially suited for use in connection with apparatusof the type shown and described in the above identified copendin'gapplications. In such apparatus, bags are made from plastic or similarnonrigid, non-creasable sheet materials. These bags are of the blockbottom type. That is, their end closures comprise side and cornerclosure flaps which are folded inwardly and secured in superposedrelation.

In the forming of paper bags, or bags of similar material, there is noparticular difiiculty involved in the centering, trueing and lining-upof the bag blanks during the feeding and the transferring operations.This is because the materials involved are relatively stiff and lightand thus do not tend to curl or wrinkle. Also such materials usuallyhave a low friction coetficient and may easily be slid over theirsupporting surface without becoming distorted. Thus ordinary mechanicalmeans acting on the edges of the bag blanks have been adequate for allalignment purposes where the blanks were made of paper and paper-likematerials.

Where, however, the bag blanks are of a relatively limp material as, forexample, a plastic material or equivalent, the conventional mechanicalarrangements which are used for centering and lining-up bag blanks madeof a more stiff or rigid material, such as paper, cannot be used. Thisis due to the fact that the relatively limp material will either bend orpleat; and, in any case, will collapse under the pushing action of thecentering and/or lining-up means.

Also, it is particularly important that special care be taken in thecentering and lining-up of bag blanks made with a relatively limpmaterial, for the various operations involved in the. formation of bagends depend for their accuracy and good execution upon the precisionwith which the bag blanks are aligned as they undergo these operations.

The present invention provides a novel arrangement for centering andlining-up bag blanks for proper feeding to thenext, station of a bagforming apparatus. This novel arrangement moreover is applicable for usewith bag blanks of soft plastic or similar materials.

According to the invention, each individual bag blank is subjected tothe action of a specially directed air stream which creates andmaintains an air cushion between the bag blank and its supporting baseso that the bag blank will not encounter any frictional resistance onthe base. It can thus be easily centered and lined-up by suitable tion.

More in particular, the centering and lining-up device, accordingto theinvention, includes a support element formed with a porous plane surfacewhich is adjustable in inclination. Suitable means are provided to blowa continuous air stream through the porous plane surface of means actingonits edges to push it in any desired directhe support element. The.width of this air stream is sufficiently large to act uniformly overthe entire under surface of the bag element; and it is sufficientlystrong to create a supporting air cushion between the bag blank and thesupport element. Centering and lining-up means are provided to act onthe edges of the bag blanks in order to shift them in one or the otherdirection, according to the particular offset of each blank itself, suchcentering and lining-up being done While the bag blank is positionedover the porous plane surface and while it is subject to the action ofthe air stream.

According to one aspect of the invention, the centering meansadvantageously comprises two opposed elements each adapted to act on onetransverse edge of a bag blank. These elements are movable between afirst inactive position, in which they are displaced from the transverseedges of the bag blank, to a second active position, in which they actupon such transverse edges. These elements also are arranged such thatwhen they are in their second position, the distance between them isslightly less than the transverse length -to the bag blank and centeredwith respect to the final desired position of the bag blank, so thatduring its passage between the opposed movable elements, it becomespushed by one or the other element, according to its offset, until itnearly assumes its final centered position. Then, due to the furthercombined approaching action of the two movable elements, the blankbecomes slightly buckled or deformed in the direction of itslongitudinal axis. When it is thereafter released, by the movement ofthe elements from their second. to their first position, it will beperfectly centered. The shifting movement of the blank from its originaloffset position to a final centered position is carried out in a verysmooth and uniform manner since, because of the air cushion, there is analmost total lack of frictional resistance between the bag blank and thesurface of the support element under it.

According to a further aspect of the invention, the lining-up meansincludes one or more aligned front stop members along which theforwardmost edge of the bag blank comes to rest in a very uniform .andeven manner. This action is made possible by the inclination of theporous plane surface of the support element, which, in cooperation withthe essentially friction-free air cushion between the support elementand the bag blank serves to induce the blank to slip easily and lightlyup against the aligned front stop members.

' Various further and more specific objects, features and advantages ofthe invention will appear from the specification given below, taken inconnection with the accompanying drawings, illustrating by way ofexample a preferred form of the invent-ion.

In the drawings:

' FIG. 1 is a plan view, partially cut away of a position of a bagforming machine utilizing the present invention;

FIG. 2 is a view taken along line 2-2 of FIG. 1; and

FIG. 3 is a side view of the apparatus as shown in FIG. 2.

FIG. 1 shows a portion of a bag making machine 10 of the type describedinmy aforementioned copending applications. In this machine, precuttubular bag blanks 12 are conveyed" along individually in the directionof the arrow A. During their movement along the machine, they firstpassthrough an alignment station 14 where they are aligned and centeredwith respect to the sides of the machine. Thereafter the blanks passthrough an opening station 16 where their end closures are formed in amanner described in said copending applications.

The effectiveness of operation of the opening station depends in greatpart upon the precision with which the individual blanks are fed intoit. Thus the alignment station 14 described more fully below, is ofconsiderable importance to the overall operation of the machine 10.

As shown in FIGS. 1-3, the alignment station 14 includes a support plate20, having a porous upper surface 22. The support plate is pivotallymounted as at 24 (FIG. 3) and its angle of inclination may be controlledby adjustment of a turnbuckle 26 connected between the support plate andthe base of the machine 10. A fan 28 (FIG. 2) is mounted under thesupport plate and connected by means of a pair of hoses '30 to blow airup through the support plate and out along its entire porous uppersurface 22.

A transversely extending drive roller 32 is mounted immediately ahead ofthe frontal or upstream edge of the support plate and is drivencontinuously by means of a drive motor (not shown), in the direction ofthe arrow B, so as to tend to urge the individual bag blanks up onto thesupport plate 20. A set of guiding rollers 34 are mounted on arms 36which in turn are attached to a common shaft 38 also extendingtransversely across the machine. Suitable means, such as a piston andcylinder assembly 40 are connected via a crank arm 42 to rotate theshaft 38 so as to move the arms 36 to bring the guiding rollers 34 downupon the roller 32. This developes a pinch effect between these rollersso that a bag blank which approaches them is drawn between them and isdriven up onto the support plate 20.

The alignment station 14 includes a centering mechanism. This centeringmechanism includes a pair of paddles 50' arranged in conjunction with alinkage system to be driven toward and away from each other. The linkagesystem is operated by means of a cam 52 which is synchronized with theoverall machine operation. More particularly, the cam 52 moves abellcrank 54 which, in turn, drives a stay rod 56. On the extremity ofthe stay rod 56, there is provided a rack 58 which meshes with a gear60*. The gear 60 is supported by and housed within a casing 62 attachedto the machine 10. A shaft 64, also rotatably mounted in the casing 62,interconnects the gear 60 and a disk plate 66. A pair of rods 68 arepivotally connected at one end thereof to displaced points 70 on thedisk plate 66. The opposite ends of these rods are connected to slidingblocks 72 and 74 on which are supported the paddles 50. A suitablereturn spring 76 cooperates with the stay rod 56 and operates to returnthe centering system to its original position after the cam 52 movesback from the bellcrank 54.

From the above, it will be seen that the action of the cam 52 on thebellcrank 54 causes the linkage system to shift the paddles 50 towardand away from each other as indicated by the arrows C. The linkagesystem is arranged such that when the paddles are at a position ofmaximum mutual displacement, the distance between them is greater thanthe transverse length of the bag blanks (as indicated by h in FIG. 1).On the other hand, when the paddles reach a position of minimum mutualdisplacement, the distance between them is slightly less than thetransverse length of the blanks. Suitable members, not shown, areprovided to adjust the relative position of the paddles 50 with respectto their respective sliding blocks 72 and 74, thus allowing anadjustment of the distance of the paddles in accordance with thetransverse length of the particular bag blanks being processed.

The alignment station 14 further includes an alignment mechanism. Thiscomprises a plurality of stop members 80 assembled on a transverselyextending shaft 82. The shaft 82 is rotatable by means of a pistonarrangement 84 so as to move the stop members from a first position asshown, where they engage the front edge of a bag blank and hold it inaligned position during centering, to a lifted second position wherethey allow the bag blank to pass through toward the opening station 16.

During operation of the apparatus, the precut bag blanks, as shown, areindividually fed by means of a suitable feeding device (not shown), tothe roller 32. At the same time, the guiding rollers 34 are lowered bymeans of various synchronizing mechanisms of the machine 10. The guidingrollers 34 and the roller 32 then cooperate to feed a bag blank onto thesupport plate 20 so that it covers the porous surface 22 of the plate.Due to the air stream caused by the fan 28 and which filters through theporous surface 22, an air cushion is developed between the bag blank andthe surface of the plate. This air cushion in effect causes the bagblank to float over the surface of the support plate. The adjustedinclination of the plate, in cooperation with the floating effect causedby this air cushion, causes the bag blank to slip down and disposeitself with one of its longitudinal edges (for example the front edgeaa) resting lightly against the stop members 80. The stop members are,of course, in their lowered position at this instant and thus areeffective both to hold the bag blank on or over the support plate and toalign it on the machine 10.

When the bag blank has thus become aligned, the centering mechanismoperates to center it. It may happen, of course, that the bag blank willbe fed to the plate 20 already centered. In this case, the centeringmechanism merely operates without actually causing any movement of thebag blank.

In the more usual case, the bag blank will be fed offset to the centerof the plate 20. When this occurs, then depending on the direction ofthe offset, one or the other of the paddles 50' will act upon one of thetransverse edges of the bag blank. If, for example, the bag blank is fedoffset in the direction of the upper paddle of FIG. 1, then, due to theaction of the cam 52 and the linkage system, this upper paddle, duringits movement from inactive to active position, will act on the uppertransverse edge (a-b) of the blank and will push the blank in an upwarddirection (as viewed in the drawing) until the blank reaches a positionwhich corresponds substantially to the desired centered position. Suchshifting is possible because the bag blank, notwithstanding the factthat it is made with a relatively limp heavy and high friction material,floats over the air cushion, and therefore, does not encounter anyfrictional resistance.

During the first centering step, the paddle will idle operate and willpass from its inactive to its active position. When the two paddlesreach the maximum approached position, they will slightly compress thebag element in the transverse direction, this compression being due tothe fact that the distance between the two paddles is slightly less thanthe height h of the bag blank itself. During the return movement of thepaddles, the bag blank will spread out flat and assume a perfectlycentered position with respect to the two paddles.

If desired, the cam 52 may be shaped, as shown in FIG. 2, to produce oneor several short movements of the paddles in order to repeat one or moretimes the final centering step. This assures a more correct and perfectcentering of the bag blank.

At the end of the centering step the piston arrangement 84- causes theshaft 82' to lift the stop members thus allowing a transfer mechanism(not shown) to shift the now centered and aligned bag blank to theopening station.

Although a particular embodiment of the invention is herein disclosedfor purposes of explanation, further modifications thereof, after studyof this specification, will be apparent to those skilled in the art towhich the invention pertains. Reference should accordingly be had to theappended claims in determining the scope of the invention.

What is claimed and desired to be secured by Letters Patent is:

1. Apparatus for centering and aligning flattened bag blanks forprocessing in a bag forming machine, said apparatus comprising a supportbase having a porous plane surface and mounted so as to be adjustable ininclination, means for blowing a continuous stream of air through saidporous plane surface, said surface extending over an area, the width ofwhich is sufficiently large to permit the blown air to act uniformlyover the entire under surface of the bag blank with sufficient intensityto create an air cushion between such bag blank and said support base,centering means and alignment means adapted to act on the edges of saidbag element in order to shift its position over said support baseaccording to its particular offset, while the bag blank is resting uponthe air cushion developed by the passage of air through said porousplane surface.

2. Apparatus according to claim 1 wherein said centering means isarranged to operate subsequent to the operation of said alignment means.

3. Apparatus according to claim 1, wherein said alignment means ismovable to allow the free passage of the bag element upon completion ofthe centering operation.

4. Apparatus according to claim 1 wherein said alignment means comprisesat least one stop member arranged along one longitudinal edge of saidsupport element, whereby a bag blank becomes aligned by the coming torest of one of its longitudinal edges against said stop member, thealmost complete lack of frictional resistance between the bag blank andthe supporting element caused by the presence of the air cushiontherebetween serving to promote smooth and uniform movement of said bagblank during such alignment.

5. Apparatus according to claim 4 wherein said centering means comprisesa linkage system and a pair of sliding blocks each carrying a paddleadapted to cooperate with and push against one transverse edge of a bagblank, said linkage system being arranged to drive said paddlessimultaneously and in synchronism with said bag forming machine.

6. Apparatus according to claim 1, wherein said centering means includestwo oppositely disposed pusher elements each arranged to act on onetransverse edge of a bag blank when said bag blank is positioned overthe porous plane surface and under the action of the air stream blowingtherethrough, and linkage means interconnecting said elements in amanner such that they are movable between a first inactive spread apartposition, in which they do not engage said transverse edges, to a secondactive approached position in which they do engage said transverseedges, said linkage mechanism maintaining said pusher elements equallydisplaced from the center of the apparatus so that during their passagefrom their first to their second positions, one of said pusher elements,depending upon the particular offset position of the bag blank, willengage its associated transverse edge of the bag blank to push it untilsaid bag blank assumes a centered position, such pushing being allowedby the almost total lack of frictional resistance due to the presence ofan air cushion under the bag blank.

7. Apparatus according to claim 65, wherein said opposed pusher elementsare displaced by an amount such that when they attain their secondactive and approached position, they become spaced apart by an amountslightly less than the height of said bag blanks so that a bag blank,during the combined approaching action of said two pusher elements,becomes slightly deformed in a longitudinal direction, and thereafter,upon being realized, during the passage of said elements from theiractive to their inactive position, said bag blank returns to a flattenedcondition in a perfectly centered position.

8. Apparatus according to claim 7, including cam means arranged toactuate said linkage mechanism to move said pusher elements, said cammeans being constructed to cause a repeating of the approaching actionof said pusher elements upon a given bag blank to improve the centeringaction thereof.

9. Apparatus according to claim 1 and including means for feeding bagblanks individually to the porous surface of said support element, saidfeeding means comprising a continuously rotating roller disposed alongthe frontal edge of said support element, at least one guiding rollerand means mounting said guiding roller for movement to bear against saidcontinuously rotating roller, such movement being synchronized with thevarious operating stations of said bag forming machine.

References Cited UNITED STATES PATENTS 1,489,045 4/1924 Stevens 271583,059,923 10/1962 Pfefier 271--58 BERNARD STICKNEY, Primary Examiner.

1. APPARATUS FOR CENTERING AND ALIGNING FLATTENED BAG BLANKS FORPROCESSING IN A BAG FORMING MACHINE, SAID APPARATUS COMPRISING A SUPPORTBASE HAVING A POROUS PLANE SURFACE AND MOUNTED SO AS TO BE ADJUSTABLE ININCLINATION, MEANS FOR BLOWING A CONTINUOUS STREAM OF AIR THROUGH SAIDPOROUS PLANE SURFACE, SAID SURFACE EXTENDING OVER AN AREA, THE WIDTH OFWHICH IS SUFFICIENTLY LARGE TO PERMIT THE BLOWN AIR TO ACT UNIFORMLYOVER THE ENTIRE UNDER SURFACE OF THE BAG BLANK WITH SUFFICIENT INTENSITYTO CREATE AN AIR CUSHION BETWEEN SUCH BAG BLANK AND SAID SUPPORT BASE,CENTERING MEANS AND ALIGNMENT MEANS ADAPTED TO ACT ON THE EDGES OF SAIDBAG ELEMENT IN ORDER TO SHIFT ITS POSITION OVER SAID SUPPORT BASEACCORDING TO ITS PARTICULAR OFFSET, WHILE THE BAG BLANK IS RESTING UPONTHE AIR CUSHION DEVELOPED BY THE PASSAGE OF AIR THROUGH SAID POROUSPLANE SURFACE.